properly handle chained @content

src/atrule/mixin.rs

@@ -24,6 +24,7 @@ impl Mixin {
     }
 }
 
+#[derive(Debug, Clone)]
 pub(crate) struct Content {
     pub content: Option<Vec<Token>>,
     pub content_args: Option<FuncArgs>,

src/builtin/meta.rs

@@ -245,7 +245,13 @@ fn content_exists(args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value>
         )
             .into());
     }
-    Ok(Value::bool(parser.content.content.is_some()))
+    Ok(Value::bool(
+        parser
+            .content
+            .last()
+            .map(|c| c.content.is_some())
+            .unwrap_or(false),
+    ))
 }
 
 pub(crate) fn declare(f: &mut GlobalFunctionMap) {

src/lib.rs

@@ -160,7 +160,7 @@ pub fn from_path(p: &str) -> Result<String> {
             global_scope: &mut Scope::new(),
             super_selectors: &mut NeverEmptyVec::new(Selector::new(empty_span)),
             span_before: empty_span,
-            content: &Content::new(),
+            content: &mut vec![Content::new()],
             in_mixin: false,
             in_function: false,
             in_control_flow: false,
@@ -206,7 +206,7 @@ pub fn from_string(p: String) -> Result<String> {
             global_scope: &mut Scope::new(),
             super_selectors: &mut NeverEmptyVec::new(Selector::new(empty_span)),
             span_before: empty_span,
-            content: &Content::new(),
+            content: &mut vec![Content::new()],
             in_mixin: false,
             in_function: false,
             in_control_flow: false,
@@ -242,7 +242,7 @@ pub fn from_string(p: String) -> std::result::Result<String, JsValue> {
             global_scope: &mut Scope::new(),
             super_selectors: &mut NeverEmptyVec::new(Selector::new(empty_span)),
             span_before: empty_span,
-            content: &Content::new(),
+            content: &mut vec![Content::new()],
             in_mixin: false,
             in_function: false,
             in_control_flow: false,

src/parse/mixin.rs

@@ -113,6 +113,11 @@ impl<'a> Parser<'a> {
         } = self.scopes.last().get_mixin(name, self.global_scope)?;
         self.eval_args(fn_args, args, &mut scope)?;
 
+        self.content.push(Content {
+            content,
+            content_args,
+        });
+
         let body = Parser {
             toks: &mut body.into_iter().peekmore(),
             map: self.map,
@@ -124,16 +129,15 @@ impl<'a> Parser<'a> {
             in_mixin: true,
             in_function: self.in_function,
             in_control_flow: self.in_control_flow,
-            content: &Content {
-                content,
-                content_args,
-            },
+            content: self.content,
             at_root: false,
             at_root_has_selector: self.at_root_has_selector,
             extender: self.extender,
         }
         .parse()?;
 
+        self.content.pop();
+
         Ok(body)
     }
 
@@ -143,7 +147,9 @@ impl<'a> Parser<'a> {
             if let Some(Token { kind: '(', .. }) = self.toks.peek() {
                 self.toks.next();
                 let args = self.parse_call_args()?;
-                if let Some(content_args) = self.content.content_args.clone() {
+                if let Some(Some(content_args)) =
+                    self.content.last().map(|v| v.content_args.clone())
+                {
                     args.max_args(content_args.len())?;
 
                     self.eval_args(content_args, args, &mut scope)?;
@@ -152,24 +158,30 @@ impl<'a> Parser<'a> {
                 }
             }
 
-            Ok(if let Some(content) = &self.content.content {
-                Parser {
-                    toks: &mut content.to_vec().into_iter().peekmore(),
-                    map: self.map,
-                    path: self.path,
-                    scopes: &mut NeverEmptyVec::new(scope),
-                    global_scope: self.global_scope,
-                    super_selectors: self.super_selectors,
-                    span_before: self.span_before,
-                    in_mixin: false,
-                    in_function: self.in_function,
-                    in_control_flow: self.in_control_flow,
-                    content: self.content,
-                    at_root: false,
-                    at_root_has_selector: self.at_root_has_selector,
-                    extender: self.extender,
-                }
-                .parse()?
+            Ok(if let Some(content) = &self.content.pop() {
+                let stmts = if let Some(body) = content.content.clone() {
+                    Parser {
+                        toks: &mut body.into_iter().peekmore(),
+                        map: self.map,
+                        path: self.path,
+                        scopes: &mut NeverEmptyVec::new(scope),
+                        global_scope: self.global_scope,
+                        super_selectors: self.super_selectors,
+                        span_before: self.span_before,
+                        in_mixin: self.in_mixin,
+                        in_function: self.in_function,
+                        in_control_flow: self.in_control_flow,
+                        content: self.content,
+                        at_root: self.at_root,
+                        at_root_has_selector: self.at_root_has_selector,
+                        extender: self.extender,
+                    }
+                    .parse()?
+                } else {
+                    Vec::new()
+                };
+                self.content.push(content.clone());
+                stmts
             } else {
                 Vec::new()
             })

src/parse/mod.rs

@@ -70,7 +70,7 @@ pub(crate) struct Parser<'a> {
     pub scopes: &'a mut NeverEmptyVec<Scope>,
     pub super_selectors: &'a mut NeverEmptyVec<Selector>,
     pub span_before: Span,
-    pub content: &'a Content,
+    pub content: &'a mut Vec<Content>,
     pub in_mixin: bool,
     pub in_function: bool,
     pub in_control_flow: bool,

tests/content-exists.rs

@@ -33,6 +33,22 @@ test!(
     "@mixin foo {\n    color: content-exists();\n    @content;\n}\n\na {\n    @include foo{color: red};\n}\n",
     "a {\n  color: true;\n  color: red;\n}\n"
 );
+test!(
+    chained_mixin_second_doesnt_have_content,
+    "@mixin foo {
+        color: content-exists();
+    }
+
+    @mixin bar {
+        @include foo;
+        @content;
+    }
+
+    a {
+        @include bar {}
+    }",
+    "a {\n  color: false;\n}\n"
+);
 error!(
     #[ignore = "haven't yet figured out a good way to check for whether an @content block exists"]
     include_empty_braces_no_args_no_at_content,

tests/mixins.rs

@@ -286,6 +286,43 @@ test!(
     }",
     "a {\n  color: red;\n}\n"
 );
+test!(
+    multiple_content_using_different_args,
+    "@mixin foo {
+        @content(1);
+        @content(2);
+    }
+
+    @mixin bar {
+        @include foo using ($a) {
+            color: $a
+        }
+    }
+
+    a {
+        @include bar;
+    }",
+    "a {\n  color: 1;\n  color: 2;\n}\n"
+);
+test!(
+    chained_content,
+    "@mixin foo {
+        @content;
+    }
+
+    @mixin bar {
+        @include foo {
+            @content;
+        }
+    }
+
+    a {
+        @include bar {
+            color: red;
+        }
+    }",
+    "a {\n  color: red;\n}\n"
+);
 error!(
     content_using_too_many_args,
     "@mixin foo {